A motor includes a base, a stator and a rotor. The base is equipped with a shaft tube having an outer circumferential wall. The stator is coupled with the shaft tube of the base and has an assembly hole. A plurality of close-fitting portions is formed between an inner circumferential wall of the assembly hole and the outer circumferential wall of the shaft tube, and an adjustment gap is formed between each two adjacent close-fitting portions. The rotor has a shaft rotatably coupled within the shaft tube of the base.
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9. A motor comprising:
a base equipped with a shaft tube having an outer circumferential wall;
a stator coupled with the shaft tube of the base and having an assembly hole, wherein a plurality of close-fitting portions is formed between an inner circumferential wall of the assembly hole and the outer circumferential wall of the shaft tube, and an adjustment gap is formed between each two adjacent close-fitting portions; and
a rotor having a shaft rotatably coupled within the shaft tube of the base, wherein the assembly hole of the stator is an imperfect circle in a radial cross section thereof, and a minimal diameter of the assembly hole is smaller than the outer tube diameter of the shaft tube such that two opposing close-fitting portions are formed as the plurality of close-fitting portions.
1. A motor comprising:
a base equipped with a shaft tube having an outer circumferential wall;
a stator coupled with the shaft tube of the base and having an assembly hole, wherein a plurality of close-fitting portions is formed between an inner circumferential wall of the assembly hole and the outer circumferential wall of the shaft tube, and an adjustment gap is formed between each two adjacent close-fitting portions; and
a rotor having a shaft rotatably coupled within the shaft tube of the base, wherein the plurality of close-fitting portions comprise at least one protrusion formed on the inner circumferential wall of the assembly hole, the shaft tube has an outer tube diameter in a radial direction thereof, and a minimal diameter of the assembly hole is smaller than the outer tube diameter of the shaft tube.
13. A motor comprising:
a base equipped with a shaft tube having an outer circumferential wall;
a stator coupled with the shaft tube of the base and having an assembly hole, wherein a plurality of close-fitting portions is formed between an inner circumferential wall of the assembly hole and the outer circumferential wall of the shaft tube, and an adjustment gap is formed between each two adjacent close-fitting portions, wherein the plurality of close-fitting portions comprise at least one protruding column formed on the outer circumferential wall of the shaft tube, wherein the at least one protruding column is axially extended on the outer circumferential wall of the shaft tube;
a positioning groove is formed on the inner circumferential wall of the assembly hole of the stator, wherein the positioning groove is axially extended on the inner circumferential wall of the assembly hole, wherein one of the at least one protruding column is coupled with the positioning groove and forms a bulged portion, wherein the bulged portion is coupled with an inner wall of the positioning groove; and
a rotor having a shaft rotatable coupled within the shaft tube of the base, and wherein a maximum diameter of the shaft tube is larger than a diameter of the assembly hole.
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3. The motor as claimed in
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16. The motor as claimed in
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1. Field of the Invention
The present invention relates to a motor and, more particularly, to a motor capable of preventing the deformation of a shaft tube thereof.
2. Description of the Related Art
Modern available motors are mainly categorized as having either a metal or a plastic shaft tube. Referring to
During assembly, the stator seat 73 generally is fitted to the outer circumferential wall of the metal shaft tube 71 in a close-fitting manner. In a case where the stator seat 73 is fitted to the metal shaft tube 71 too closely, the metal shaft tube 71 will be excessively compressed by the stator seat 73. In this case, the metal shaft tube 71 will be easily deformed due to the compression of the stator seat 73 if there is no buffering between the metal shaft tube 71 and the stator seat 73. In addition, the deformed portions of the metal shaft tube 71 will further compress the bearings 74, causing the bearings 74 to be deformed, damaged or out of position. As a result, the lifespan of the motor 7 is decreased. Also, it is difficult to manufacture and further process the motor 7, and additional manpower will be required to manually mount the metal shaft tube 71 on the casing seat 72, making it costly to produce the motor 7.
Referring to
The plastic shaft tube 811 of the motor 8 may be integrally manufactured in a manner of injection molding, which is particularly advantageous over the motor 7 in terms of manufacturing, assembly and cost. During assembly, the stator 82 may be fitted to an outer circumferential wall of the plastic shaft tube 811 in a close-fitting manner. In contrast to a metal shaft tube 71 and due to the absence of buffering between the plastic shaft tube 811 and the stator 82, the plastic shaft tube 811 tends to be deformed more easily when the plastic shaft tube 811 is excessively compressed by the stator 82.
To avoid the above potential problems of the motor 8, Taiwan Patent Publication No. 519259 discloses a motor as shown in
It is therefore the primary objective of this invention to provide a motor in which the shaft tube is prevented from being excessively compressed by the stator during assembly of the motor.
It is therefore the secondary objective of this invention to provide a simple-structured motor in which deformation of the shaft tube is avoided.
The invention discloses a motor comprising a base, a stator and a rotor. The base is equipped with a shaft tube having an outer circumferential wall. The stator is coupled with the shaft tube of the base and has an assembly hole. A plurality of close-fitting portions is formed between an inner circumferential wall of the assembly hole and the outer circumferential wall of the shaft tube, and an adjustment gap is formed between each two adjacent close-fitting portions. The rotor has a shaft rotatably coupled within the shaft tube of the base.
The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
In the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the term “first”, “second”, “third”, “fourth”, “inner”, “outer” “top”, “bottom” and similar terms are used hereinafter, it should be understood that these terms are reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention.
In
The base 1 is mounted with a shaft tube 11 made of either a metal or plastic material, with the plastic one preferred. The shaft tube 11 has an outer circumferential wall 111, with an opening 112 formed on a side thereof. At least one bearing 12 is received within the shaft tube 11. The bearing 12 may be settled into the shaft tube 11 via the opening 112. In the embodiment of
The stator 2 is mounted on the base 1 and has an assembly hole 21 which allows the shaft tube 11 to be fitted therethrough. In the embodiment, the stator 2 that drives the rotor 3 may consist of a plurality of silicon steel plates 22, a plurality of coils 23 and two isolation members 24. The assembly hole 21 is formed by stacking the plurality of silicon steel plates 22 with one another as a stack entity. The two isolation members 24 are coupled with two ends of the stack entity of the plurality of silicon steel plates 22. The plurality of coils 23 may wind around certain portions of the plurality of silicon steel plates 22 and the isolation members 24. Note the plurality of silicon steel plates 22 may be integrally formed as the stack entity in an injection molding manner.
Specifically, as shown in
The rotor 3 comprises a hub 31 and a permanent magnet 32. The hub 31 has a shaft 311 rotatably coupled within the shaft tube 11 of the base 1. The permanent magnet 32 is an annual magnet coupled with an inner circumferential wall of the hub 31. There is an air gap between the permanent magnet 32 and the stator 2.
During operation of the motor, the stator 2 generates an alternating magnetic field including magnetic flux flowing in the air gap, causing the stator 2 to react with the permanent magnet 32 via the alternating magnetic field, thus making the rotor 3 rotate.
The motor of the invention is characterized by that the stator 2 may be fitted to the outer circumferential wall 111 of the shaft tube 11 in a close-fitting manner via the close-fitting portions 4 formed between the inner circumferential wall of the assembly hole 21 and the outer circumferential wall 111 of the shaft tube 11, thereby providing a better fitting between the stator 2 and the shaft tube 11. More importantly, although the stator 2 and the shaft tube 11 are closely fitted with each other, the shaft tube 11 may be prevented from being excessively compressed by the stator 2 via the adjustment gaps 5 between each two adjacent close-fitting portions 4, thus further avoiding deformation, damaging or shifting of the bearing 12 when the bearing 12 is subjected to the direct compression of the shaft tube 11. Moreover, when the shaft tube 11 is a plastic shaft tube which deforms due to the hot-swelling and cool-shrinking effect, the shaft tube 11 may be prevented from being excessively compressed by the stator 2 via the buffering effect provided by the adjustment gaps 5. In general, the adjustment gaps 5 formed between each two adjacent close-fitting portions 4 may provide the space flexibility for the shaft tube 11 when the shaft tube 11 is deformed due to an undesired event.
Based on the structure of the motor, the close-fitting portions 4 and the adjustment gaps 5 may be embodied in various ways described below.
In
In
In
In
Specifically, as shown in
Based on the motor structures previously described, to further improve the motor, the motor of the invention may further include at least one of the following secondary features or any combination thereof, as elaborated below.
An enclosed portion 115 may be formed on another end of the shaft tube 11, as shown in
A side of the enclosed portion 115 inside the shaft tube 11 may have a planar surface. Based on this, the shaft 311 may be positioned more easily during assembly, providing a better perpendicularity of the shaft 311.
Based on the embodiment described in
The motor of the invention may be applied to a heat-dissipating fan, such as an air-blowing fan or an axial flow fan. In
According to the above description, the adjustment gaps 5 may be configured to provide the space flexibility for deformation of the shaft tube 11, thereby avoiding deformation, damaging or shifting of the shaft tube 11 when the shaft tube 11 is subjected to excessive compression of the stator 2 during assembly of the motor. In this way, deformation, damaging or shifting of the shaft tube 11 may be avoided, and the convenience of assembly is also increased, thus achieving advantages such as prolonging lifespan, decreasing noise and improving quality of the motor.
Although the invention has been described in detail with reference to its presently preferable embodiments, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims.
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Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Nov 30 2009 | HORNG, ALEX | SUNONWEALTH ELECTRIC MACHINE INDUSTRY CO , LTD | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 023837 | /0614 | |
Jan 25 2010 | Sunonwealth Electric Machine Industry Co., Ltd. | (assignment on the face of the patent) | / | |||
Aug 01 2019 | SUNONWEALTH ELECTRIC MACHINE INDUSTRY CO , LTD | SUNONWEALTH ELECTRIC MACHINE INDUSTRY CO , LTD | CHANGE OF ASSIGNEE ADDRESS | 049934 | /0557 |
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